In recent years, wafer backside laminating methods have been widely used as a process for cutting and separating (dicing) semiconductor wafers that have been produced with a large diameter into smaller semiconductor elements (semiconductor chips), and then bonding (die bonding) each of these semiconductor elements onto a support member such as a lead frame or an organic substrate.
When a semiconductor device is manufactured by a wafer backside laminating method, using a film adhesive, then as shown in FIG. 3, first, (1) a film adhesive 11 is laminated to the backside of a semiconductor wafer 10, and then (2) a dicing tape 14, comprising a pressure-sensitive adhesive layer 12 disposed on a base film 13, is laminated to the other side of the film adhesive, (3) the semiconductor wafer is divided into individual semiconductor elements by dicing, and (4) each individual semiconductor element is picked up with the film adhesive, bonded (die bonded) to a support member, and then subjected to a series of processes such as the wiring of metal wire 15, and heat curing, thereby forming a semiconductor device 16.
Furthermore, an alternative method is an individual film bonding method. In this individual film bonding method, (1) a lone film adhesive is cut into individual sections, (2) each individual section of the film adhesive is bonded to a support, and (3) an individual semiconductor element produced by dicing is bonded (die bonded) to the film adhesive bonded to the support member, and then subjected to a series of processes such as the wiring of metal wire, and heat curing, thereby forming a semiconductor device.
In the wafer backside laminating method described above, because the semiconductor wafer the film adhesive are diced simultaneously, and a semiconductor element with a film adhesive is then bonded to a support member, a separate apparatus for dicing the film adhesive and then bonding each individual section of film adhesive to a support member is not needed, meaning a conventional silver paste assembly apparatus can be used, either as is, or with improvements made to portions of the apparatus such as the addition of a hot plate. As a result, amongst the various assembly methods using film adhesives, wafer backside laminating is attracting considerable attention as a method that enables comparatively cheap manufacturing costs.
However, in a method that employs a film adhesive using a wafer backside laminating method, because two bonding steps, that is, a step for bonding together the film adhesive and the dicing tape, and then a step for bonding the resulting laminated film to the backside of a semiconductor wafer, are required prior to the dicing step, further simplification of the operation is still being sought. Films in which the pressure-sensitive adhesive layer and the adhesive layer have been incorporated into a single layer have been proposed as films capable of achieving such a simplification (for example, Japanese Laid-Open Publication No. Hei 2-32181 and Japanese Laid-Open Publication No. Hei 8-53655).
Furthermore, another possible method involves preparing an integrated sheet in which a film adhesive has been provided on a dicing tape (hereafter, this type of sheet is referred to as a dicing/die bonding sheet), and then laminating this sheet to a wafer. However, with an integrated dicing/die bonding sheet comprising a film adhesive provided on a dicing tape, because the period between manufacture and use of the sheet, during which time the adhesive layer of the film adhesive is in contact with the pressure-sensitive adhesive layer of the dicing sheet, is inevitably long, a problem arises in that the two layers interact, meaning that during the process for picking up individual semiconductor elements with the film adhesive laminated thereto, the film adhesive and the dicing tape may not separate satisfactorily.